The development of disk drive systems is continuing at a substantial pace as market requirements continue to evolve. Disk drives are finding application in a wide variety of systems ranging from full function notebook style computers to high-performance, single-user, multitasking workstations and further to broadly generalized, high-performance, multi-user computer systems. Although the disk drive design requirements for use in such a diverse universe of applications would appear to be substantial and varied, there are a number of common requirements. These requirements include high-reliability, low power consumption, high data access and transfer speeds and minimum form-factor size and weight for the storage capacity provided.
For workstations and high-performance, generalized computer systems, the requirements on disk drive designs tend to accentuate the need for high-capacity and substantial data access and transfer rates. In addition, there is a desire to have flexibility in the specific control implementation of such high performance drives that can be tailored or enhanced to slightly or possibly even significantly improved the performance of the drive depending in the actual circumstances of the application.
Prior high-performance disk drive systems have typically relied on substantial mechanical performance enhancements to boost data access speed. Such improvements have included providing multiple data read/write heads per disk surface. In some embodiments the multiple heads have been carried on a common actuator arm, thereby reducing the length of a data seek stroke to arrive at a desired track location. Alternately, multiple actuator assemblies have been utilized to allow independent data seeks to occur simultaneously.
While these are the mechanical achievements the conventional approach to enhancing data transfer rate, from the point of view of the control electronics has been to employ specific, dedicated electronic subsystems to manage the independent specific function necessary to operate the drive system. While generally capable of obtaining the high data transfer rates desired, such a design necessarily freezes the architecture of the drive control system. Changes in the specific nature of the mechanical or high-level drive control operation requires at least a corresponding alteration to the underlying electronic hardware architecture, if not a complete redesign. Further, the cost associated with the development of the initial dedicated electronic subsystems as well as to implement any subsequent design modifications results in a substantial time and cost investment.